Drucker entered the comics field by assisting Bert Whitman on the Publishers-Hall newspaper comic strip "Debbie Dean" in 1947 when he was 18, based on a recommendation from Will Eisner. He then joined the staff of National Periodical Publications (DC Comics), where he worked as a retoucher. While at DC, Drucker also ghosted "The Mountain Boys", Paul Webb's regular gag panel for Esquire Magazine. Early in the 1950s, Drucker left his DC staff gig and began doing full-time freelance work for a number of comic book publishers such as Dell, Atlas and St. John's, as well as several humor and war titles for his former employer.
In the fall of 1956, shortly after the departure of Mad Magazine's founding editor Harvey Kurtzman, Mort Drucker answered a want ad placed by Mad in the New York Times. Associate Editor Nick Meglin was impressed with the portfolio of hundreds of comics Drucker had created and illustrated, including war comics, westerns, and humor comics, and quickly took it for review to Bill Gaines and Al Feldstein, who were engrossed in a Brooklyn Dodgers game. "If the Dodgers win you're hired," Gaines gleefully informed Drucker. Luckily, they did,
and Drucker was enlisted on the spot. After joining the Usual Gang of idiots, Drucker's
talent for caricature came to the fore.
In 2012, Drucker discussed his art style, and how he applied it to his Mad assignments: "I've always considered a caricature to be the complete person, not just a likeness. Hands, in particular, have always been a prime focus for me as they can be as expressive of character as the exaggerations and distortions a caricaturist searches for. I try to capture the essence of the person, not just facial features ...
I've discovered through years of working at capturing a humorous likeness that it's not about the features themselves as much as the space between the features. We all have two eyes, a nose, a mouth, hair, and jaw lines, but yet we all look different. What makes that so is the space between them...
...The artist is actually creating his own storyboard for the film. I become the camera and look for angles, lighting, close-ups, wide angles, long shots — just as a director does to tell the story in the most visually interesting way he can. My first sketches are as much composition and design ideas as they are character and action images ... I don't want to get too involved in the juicy parts since some of what I'm doing will be modified or discarded as I get further involved in the storytelling. I then stand back and look at the page as a complete unit to make sure it's designed well: 'Hmmm, three close-up panels in a row of characters talking. Better change that middle panel to a far shot. Maybe make that panel an open vignette.' ... Then I place the facing pages together and look at how the spread holds together, and sometimes make changes based on that."
Drucker's portraits have also frequently occupied the cover of Time Magazine-over fifteen have appeared since 1970-and seven of the original drawings have found a home in the National Portrait Gallery of the Smithsonian Institution. He was recognized for his work with the National Cartoonists Society Special Features Award (1985, 1986, 1987, 1988), its Reuben Award (1987), Eisner Award Hall of Fame (2010) and induction into the Society's Hall of Fame (2017).